The low-frequency carbody cross swaying of some CRH high-speed trains were emerged in the process of line tests, whichcaused a significant deterioration for passengers ride comfort. In order to obtain the effective measures to suppress the carbody swaying, themultiple rigid body dynamic model of a high-speed vehicle was set up firstly. Then, based on the time domain dynamic simulations, the mainfactors influencing the low-frequency carbody swaying were obtained. At last, the root lotus analysis was used to investigate the effect ofcritical parameters on the low-frequency carbody swaying. It was shown that, proper selection of suspension parameters, wheel railparameters and carbody mass parameters could avoid the offensive low-frequency carbody swaying.